Environmental problems of fluorocarbons and hydrocarbons have created the need for an environmentally acceptable means of dispensing aerosol products. Other propellants are available but often they are not compatible with the product. Thus, a means of separating the product from the propellant is needed and can be accomplished by the utilization of an internal product containment sack. The use of such a sack also makes it possible to use air pressure as the propelling means.
If air pressure is used, refrigerating equipment that would otherwise be required to keep the propellant in a liquid form is not necessary. This further reduces chances of fluorocarbon escaping into the atmosphere due to leaks in the equipment.
The present invention represents a modification of the pressurized dispenser in Applicant's copending patent application, Ser. No. 781,784 filed Mar. 28, 1977, now abandoned and also an additional application filed Dec. 14, 1977, Ser. No. 860,354, U.S. Pat. No. 4,159,789 dated July 3, 1979.
Cost of new tooling and changes in packaging methods are not readily accepted by the manufacturers of aerosol products. These costs along with cost of the product and containers must be passed to the consumer. Should the resultant cost be excessive, the product cannot be competitive with other non-aerosol alternatives. The present improved invention is devised to keep the aerosols competitive and environmentally acceptable. Other dispensers in the art having a collapsible sack are shown in the following U.S. Patents: Nos.
3,549,058 Inventor: E. J. Bolk PA1 3,477,195 Inventor: C. D. Chambers PA1 2,816,691 Inventor: L. T. Ward PA1 3,731,854 Inventor: D. E. Casey PA1 3,169,670 Inventors: P. Hrebenak & L. Zuckerman
Also, a self-heating shave cream manufactured by the Gillette Company utilizes a sack contained inside the dispenser.
The Bolk and Chambers Patents employ a bellows shape and have similar disadvantages that were described in the Casey Patent. Another disadvantage is the nature of their construction. They prevent efficient utilization of the pressurizing agent since the pressure applied to the sack is effective from the bottom surface area. This means the dispensing force is equal to (PSI TT D.sup.2, whereas, a sack of tubular shape has the effective pressure force over its entire surface (length X the TT R.sup.2 X PSI). The bellows-shaped sacks also require special manufacturing processes and cannot be readily adapted to providing a use of the propellant for nozzle clearing. The Bolk Patent further limits the method in which the propellant can be introduced within the pressure chamber. It requires a plugged hole in the container since the sack, when installed, closes off the top opening in the container cover. PG,3
The Casey Patent illustrates a sack that has longitudinal pleats. The shape while better utilizing the pressure is subject to undesired buckling of the walls that could prevent total dispensing of a product. Additionally, the sack is sealingly attached to the valve assembly which means filling must be accomplished through the valve. This causes slower and more costly filling. It also prevents the use of the propellant for nozzle clearing. It, too, requires a plugged hole in the container for pressurizing.
The Ward and Hrebenak/Zuckerman Patents describe a flexible balloon-shaped sack. This sack can prove to be the most unreliable because of its uncontrolled collapsing nature. Since the pressure in the container is always pushing toward the valve when dispensing, it can push a portion of the sack over the valve opening, thus, blocking off the product. It is also designed to be attached in such a manner that limits its use since, it will not allow use of the propellant for nozzle clearing. Also unless it is pre-filled and secured to the valve prior to insertion within the container, the sack is subjected to being inadvertently pushed inside the container rendering it useless.
The Gillette dispenser appears to be similar to the Ward invention, although it employs a semi-rigid sack somewhat resembling a test tube. Although it is in the market place, its packaging requirements have proven to be too costly for most products. The filling of both the product and pressurizing agent requires extensive assembly while in a refrigerated environment. Although this may not be so uncommon the Gillette method also requires that the sack be filled with the product and heat-sealed to the valve while in such an environment prior to being placed within a container already having the required amount of propellant. The sack design is also quite stiff at the top and bottom, thus, restricting it from efficiently collapsing. It does not appear to be adaptable to liquid spray-type products.
The above application Ser. No. 781,784 illustrates a sack having an improved shape that efficiently utilizes the pressure but does not provide an economical method of assembly. It also requires pressurizing through a plugged hole.
The second application Ser. No. 860,354 now U.S. Pat. No. 4,159,789, provides a sack having further improved collapsing features. The primary disadvantage of this unit is that it is not readily adapted to existing valves and containers. This causes a resistance by the industry due to change over and tooling cost. It also is mainly designed to utilize a plurality of sacks. This is yet to be tried by the industry.